Jet device for improving precooling effect of vehicle-mounted liquid hydrogen tank

Abstract

The invention belongs to the technical field of liquid hydrogen stations, and particularly relates to a spraying device for improving the precooling effect of a vehicle-mounted liquid hydrogen tank, the spraying device comprises a spraying inlet pipeline, a Laval nozzle, a spraying precooling pipeline and an atomizing nozzle, the inlet end of the spraying inlet pipeline is connected with the vehicle-mounted liquid hydrogen tank, the outlet end of the spraying inlet pipeline is connected with the inlet end of the Laval nozzle, and the spraying precooling pipeline is connected with the atomizing nozzle. The outlet end of the Laval spray pipe is connected with the inlet end of the spraying pre-cooling pipeline, and a plurality of atomizing nozzles are uniformly distributed on the spraying pre-cooling pipeline. The multi-channel structure and the atomizing nozzle are adopted for improving the flow channel and the atomizing effect of fluid, the use effect is excellent, the high use and popularization value is achieved, and the device is suitable for large-scale storage tanks including but not limited to a vehicle-mounted liquid hydrogen storage tank and a low-temperature liquid storage tank.

Description

Technical Field

[0001] The present invention relates to an injection device for improving the precooling efficiency of a vehicle-mounted liquid hydrogen tank, which is mainly used in the field of new energy and relates to the application field of vehicle-mounted liquid hydrogen tanks. Background Art

[0002] Precooling of on-board liquid hydrogen tanks is a key step in the commissioning process of on-board liquid hydrogen tanks. The precooling nozzle is a core component that plays a key role in precooling of on-board liquid hydrogen tanks. As liquid hydrogen tanks tend to be used in civilian forms, storage tanks are about to transform from large to small, so the precooling method of liquid hydrogen tanks has also changed from precooling of large storage tanks to precooling of small on-board liquid hydrogen tanks, and the precooling flow rate has decreased accordingly. For small-volume on-board liquid hydrogen tanks, it is necessary to ensure the temperature drop rate, local temperature difference and overall temperature difference during the precooling process, and the requirements for precooling nozzles are becoming higher and higher.

[0003] Traditional nozzles are mainly used for precooling large-volume liquid hydrogen storage tanks. Due to the large overall area, it is easy to cause insufficient and uneven precooling and low precooling efficiency. In order to consider the precooling safety in the early stage of precooling, liquid nitrogen is usually introduced for precooling. Therefore, the precooling injection pipeline is filled with nitrogen, which is easy to cause gas-liquid blockage or reflux in the precooling injection pipeline, thereby affecting the initial precooling effect.

[0004] In large-scale vehicle-mounted liquid hydrogen tanks, a single nozzle is usually used for directional injection, which will result in only a local pre-cooling nozzle blind area instead of the pre-cooling area, resulting in low pre-cooling efficiency. In addition, since a single nozzle is directly connected to the nozzle, it is easy for a single nozzle to cause nozzle blockage, thereby causing a bias flow effect on the entire spray pipeline, causing liquid hydrogen or liquid nitrogen droplets that are not fully atomized to drip directly to the bottom of the tank, causing the temperature at this location to drop rapidly and the temperature difference with other locations to increase rapidly, resulting in the tank pre-cooling process being difficult to meet the corresponding temperature river speed, local temperature difference and overall temperature difference requirements. Summary of the invention

[0005] In view of the above problems, an object of the present invention is to provide a vehicle-mounted liquid hydrogen tank injection device that can improve flow characteristics and enhance pre-cooling effects.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an injection device applied to a small vehicle-mounted liquid hydrogen tank to improve the precooling effect of the vehicle-mounted liquid hydrogen tank, comprising a spray inlet pipe, a Laval nozzle, a spray precooling pipe, and an atomizing nozzle. The inlet end of the spray inlet pipe is connected to the vehicle-mounted liquid hydrogen tank, the outlet end of the spray inlet pipe is connected to the inlet end of the Laval nozzle, the outlet end of the Laval nozzle is connected to the inlet end of the spray precooling pipe, and a plurality of atomizing nozzles are evenly distributed on the spray precooling pipe.

[0007] Preferably, the spray inlet pipe is a cylindrical pipe with a length of 100 mm and a width of 20 mm. The front end of the Laval nozzle gradually shrinks toward the middle, and the middle gradually expands toward the rear end. The spray precooling pipe is cylindrical, and 30-50 atomizing nozzles are arranged per square centimeter on the spray precooling pipe. During spraying, spray is performed around the inside of the liquid hydrogen tank, and the precooling efficiency is greatly enhanced during precooling.

[0008] In order to achieve heat preservation, the spray inlet pipe includes an inner liner, an insulation layer, a vacuum layer and an outer wall from the inside to the outside.

[0009] The atomizing nozzle adopts a fan-shaped outlet, and the central angle range of the fan-shaped outlet is controlled between 90° and 120°. Its main function is to increase its pre-cooling effect and the gas-liquid mixture will not cause the nozzle to be blocked.

[0010] In order to ensure the spraying effect, in a preferred embodiment of the present invention, the atomizing nozzle includes a nozzle body, a gas-liquid diversion inlet, a tapered cavity, a jet section, an adjustable rolling joint and a nozzle outlet, the gas-liquid diversion inlet is arranged at the inlet end of the nozzle body, the tapered cavity is connected to the outlet end of the gas-liquid diversion inlet, and the diameter of the tapered cavity gradually decreases from one end close to the gas-liquid diversion inlet to the other end away from the gas-liquid diversion inlet, the jet section is connected to the outlet end of the tapered cavity, the diameter of the jet section is larger than the diameter of the outlet end of the tapered cavity, and the diameter of the jet section gradually decreases from one end close to the tapered cavity to the other end away from the tapered cavity, the nozzle outlet is arranged at the outlet end of the jet section, and the nozzle outlet is movably connected to the outlet end of the jet section through an adjustable rolling joint.

[0011] In order to increase the injection speed, a gas-liquid guide device is provided at the gas-liquid guide inlet, and the gas-liquid guide device includes a liquid guide inlet and multiple gas guide inlets. The gas guide inlets are evenly arranged along the circumference of the liquid guide inlet, and the diameter of the liquid guide inlet is larger than the diameter of the gas guide inlet.

[0012] The present invention adopts the above technical solution, and has the following characteristics:

[0013] 1. The present invention includes a spray pipe and a nozzle structure. By setting a structure of uniformly distributed internal liquid and gas diversion and a tapered section, the fluid characteristics are improved, the atomization effect is improved, and the cost performance is increased, thereby ensuring that the precooling nozzle can ensure the precooling effect during the precooling process and the initial stage of precooling of a small vehicle-mounted liquid hydrogen tank.

[0014] 2. The present invention increases the speed by installing a Laval nozzle in the middle of the spray inlet pipe and the spray annular outlet pipe, thereby reducing the impact caused by insufficient initial gas velocity in the early stage of precooling, thereby increasing the adaptability of the working conditions of the later nozzle precooling.

[0015] 3. The present invention is provided with an adjustable rolling joint, which increases the direction adjustment of the rolling joint, increases the coverage of the spray by angle setting, and improves the overall spray effect. The design of the atomizing nozzle can increase the atomization effect of the spray and avoid the occurrence of dripping in the initial stage of pre-cooling.

[0016] In summary, the present invention adopts a multi-pore structure and an atomizing nozzle to improve the flow channel and atomization effect of the fluid, has excellent use effect, has high use and promotion value, and is suitable for large-scale storage tanks, including but not limited to vehicle-mounted liquid hydrogen storage tanks and cryogenic liquid storage tanks.

[0017] The significant advantages of the present invention are in the following aspects:

[0018] (1) The spray device as a whole adopts three structures: spray inlet pipe, Laval nozzle and spray precooling pipe. The structure is novel, the precooling efficiency is significantly improved, and no damage is caused to the structure.

[0019] (2) The inlet end of the overall pre-cooling structure adopts a vacuum layer pre-cooling pipeline, and its structure is mainly divided into an outer wall, an insulating vacuum layer and an inner liner. The insulating vacuum layer contains a variety of insulating materials for winding to ensure that the liquid hydrogen enters the pipeline for initial pre-cooling to produce a vaporization reaction to reduce its heat loss, thereby ensuring that the subsequent pre-cooling process can be completed efficiently in a short time, saving time and cost.

[0020] (3) The device is provided with a Laval nozzle in the middle of the spray inlet pipe and the spray precooling pipe to transmit and accelerate the initial precooling occurring in the spray inlet pipe, thereby avoiding the problem of gas-liquid retention in the traditional precooling pipe due to the slow reaction in the late stage of precooling.

[0021] (4) Considering the practicality of the Laval nozzle, the device is provided with a guide strip in the spray inlet pipe for transmitting the liquid in the spray inlet pipe. The guide strip structure is arranged to pass through the Laval nozzle to the center body of the spray precooling pipe. The gas directly enters the spray precooling pipe and the nozzle inlet end through the Laval nozzle, so that the precooling reaction occurs smoothly, eliminating the uncertainty of the Laval nozzle being applied to gas rather than liquid.

[0022] (5) The end of the device is set as a spray precooling pipeline, and a plurality of precooling nozzles are arranged inside the device, with a size of 30-50 precooling nozzles per square meter, which increases the precooling contact area. In addition, since a central body is arranged inside to transmit liquid, the gas-liquid barrier and retention caused by the setting of multiple nozzles are reduced, thereby improving the precooling efficiency.

[0023] (6) The pre-cooling nozzle is independently designed, thus eliminating the limitations of the gas-liquid inlet of the traditional nozzle. The liquid is directly introduced through the guide strip, and the gas is transmitted through the pipeline. The inner cavity of the nozzle is set to a structure that is wide in the front and narrow in the back, which can speed up the gas and liquid again in a small range. The method is relatively novel, and the nozzle mouth is set to a rolling spherical device and the center angle of the nozzle is set to 90°-120°, which increases the flexibility and efficiency of pre-cooling, thereby improving the pre-cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a side view of the injection device for improving the precooling efficiency of the vehicle-mounted liquid hydrogen tank of the present invention;

[0025] Figure 2 is a side view of the Laval nozzle of the present invention;

[0026] Figure 3 is a cross-sectional view of the nozzle structure of the present invention;

[0027] Figure 4 It is a top view of the nozzle structure of the present invention. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0029] like Figure 1 The shown spray device is applied to a small vehicle-mounted liquid hydrogen tank to improve the precooling effect of the vehicle-mounted liquid hydrogen tank, comprising a spray inlet pipe 1, a Laval nozzle 2, a spray precooling pipe 3, and an atomizing nozzle 4, wherein the inlet end of the spray inlet pipe 1 is connected to the vehicle-mounted liquid hydrogen tank, the outlet end of the spray inlet pipe 1 is connected to the inlet end of the Laval nozzle 2, the outlet end of the Laval nozzle 2 is connected to the inlet end of the spray precooling pipe 3, and a plurality of atomizing nozzles 4 are evenly distributed on the spray precooling pipe 3, wherein the spray pipe (spray inlet pipe 1, Laval nozzle 2, spray precooling pipe 3) is arranged 100 mm above the liquid inlet side of the horizontal vehicle-mounted liquid hydrogen tank, and a plurality of atomizing nozzles 4 are arranged in the spray precooling pipe 3 for spraying the storage tank.

[0030] Specifically, the left side of the spray inlet pipe 1 is connected to the precooling source, and can be directly extended from left to right to connect with the inlet section 5 of the Laval nozzle 2, and the right outlet section 6 of the Laval nozzle 2 can be directly connected to the inlet of the spray precooling pipe 3, wherein the spray inlet pipe 1, the Laval nozzle 2 and the spray precooling pipe 3 are all on the same horizontal line, and the horizontal position is about 10 cm above the liquid inlet side of the horizontal vehicle-mounted liquid hydrogen tank. When in use, liquid nitrogen or liquid hydrogen enters the Laval nozzle 2 through the spray inlet pipe 1 for pressurization and speed increase, and then separates the gas and liquid through the guide strip. After separation, the gas and liquid enter the spray precooling pipe 3 and arrive at the atomizing nozzle 4 for spray precooling.

[0031] like Figure 2 The Laval nozzle 2 shown includes an inlet section 5 and an outlet section 6. The liquid flowing in through the spray inlet pipe 1 directly passes through the Laval nozzle 2 through the guide strip and enters the liquid guide inlet 15. The gas generated after the initial pre-cooling reaction flows into the inlet section 5 of the Laval nozzle 2 due to the increased pressure after the reaction, passes through the narrow throat of the front half to increase speed and pressurize, and finally escapes from the rear half of the Laval nozzle 2. Since the gas and liquid are accelerated when flowing at the same high speed, the pressure around them becomes smaller due to the increase in speed, so that the gas and liquid enter the nozzle more quickly, thereby achieving a basic pre-cooling initial speed.

[0032] like Figure 3 , 4As shown, the atomizing nozzle includes a nozzle body 11, a gas-liquid guide inlet 7, a tapered cavity 8, a jet section 9, an adjustable rolling joint 10 and a nozzle outlet 12. A gas-liquid guide device 13 is arranged inside the nozzle body 11. The gas-liquid guide device includes a liquid guide inlet 15 and a plurality of gas guide inlets 14. The gas guide inlet 14 is evenly arranged along the circumference of the liquid guide inlet 15, and the diameter of the liquid guide inlet 15 is larger than the diameter of the gas guide inlet 14. Molecular films are arranged at the gas-liquid guide device and the gas-liquid guide inlet 7 to facilitate the entry of gas and liquid without turbulence. Liquid nitrogen and liquid hydrogen fluids enter through the liquid guide inlet 15, and nitrogen and hydrogen both enter the tapered cavity through the gas guide inlet 14. The purpose of arranging a plurality of gas guide inlets 14 is to allow the gas-liquid mixture to have A larger initial velocity is achieved, thereby reducing the retention of gas and liquid in the nozzle body. The shear force of the surrounding gas is enhanced by controlling the tapered cavity 8, and the atomization effect of the nozzle is enhanced. The length and diameter of the tapered cavity 8 are controlled within a set range. The diameter of the tapered cavity 8 gradually decreases from one end close to the gas-liquid diversion inlet 7 to the other end away from the gas-liquid diversion inlet 7. The length of the tapered cavity should take into account the size of the overall nozzle, so it should not be too long. If it is too long, the chemical properties of the gas and liquid will affect its flow loss and reduce the flow coefficient of the nozzle. Therefore, the smaller the diameter of the tapered cavity 8, the smaller the outlet area at the same liquid nitrogen or liquid hydrogen flow rate, the greater the difference in pressure between the internal and external liquid nitrogen or liquid hydrogen, the faster the liquid nitrogen or liquid hydrogen is sprayed out, the stronger the shear force formed by the gas around the nozzle, and the better the atomization effect.

[0033] The outlet end of the tapered cavity 8 is connected to the jet section 9, the adjustable rolling joint 10 and the nozzle outlet 12 in sequence. The adjustable rolling joint 10 can be adjusted in position before construction to meet the requirements of the corresponding process parameters and precooling schemes. The adjustable rolling joint 10 is used to adjust the spray angle before the nozzle is installed. The spray angle is adjusted according to the actual process parameters such as flow, pressure, temperature, etc. and precooling schemes such as liquid nitrogen precooling, liquid hydrogen precooling, etc., to enhance the coverage of the nozzle spray and improve the uniformity of the temperature drop during the precooling of the storage tank. After passing through the tapered cavity 8, the liquid nitrogen or liquid hydrogen fluid passes through the jet section 9 and the adjustable rolling joint 10 and enters the nozzle outlet 12.

[0034] Further, the nozzle outlet 12 can adopt a fan-shaped outlet, and the atomization effect of liquid hydrogen precooling can be controlled by the fan-shaped height. After the liquid passes through the fan-shaped outlet, a uniform and flat fan-shaped liquid surface is formed, which has good symmetry. The center angle of the fan-shaped outlet and the angle of the liquid fan-shaped liquid surface are related to each other. The angle of the fan-shaped liquid surface can be controlled by controlling the center angle to increase the atomization effect of liquid hydrogen or liquid nitrogen. Further, the center angle of the fan-shaped outlet is between 90° and 120°, and the fan-shaped height can also be controlled by pressure to increase the atomization effect of liquid hydrogen or liquid nitrogen.

[0035] Liquid nitrogen or liquid hydrogen fluid separates gas and liquid through the guide strips in the spray pipe and finally enters the Laval nozzle 2. The gas entering the Laval nozzle 2 will gain a higher speed and then enter the atomizing nozzle 4 of the spray precooling pipe 3, while the liquid directly enters the inner cavity of the spray precooling pipe 3 through the guide strips to mix with the gas and enter the nozzle for reaction precooling. A gas-liquid guide device is provided in the nozzle body, which is used to pass gas and liquid, and each inlet of the gas-liquid guide device is connected to the tapered cavity 8, and the outlet end of the tapered cavity 8 can be connected to the adjustable rolling joint 10 and the nozzle outlet 12 through a connecting pipe. Therefore, the present invention can make the storage tank fully exert its precooling efficiency in the early stage of precooling, so that the entire precooling process can be carried out more quickly and cost-effectively.

[0036] Finally, it should be noted that: the embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above specific implementations, which are merely illustrative and not restrictive. For those of ordinary skill in the art, other different forms of changes or modifications can be made without departing from the scope of protection of the present invention and the claims, all of which are within the protection scope of the present invention.

Claims

1. A spray device for improving the precooling effect of a vehicle-mounted liquid hydrogen tank, characterized in that: It includes a spray inlet pipe, a Laval nozzle, a spray precooling pipe, and an atomizing nozzle. The inlet end of the spray inlet pipe is connected to the on-board liquid hydrogen tank, the outlet end of the spray inlet pipe is connected to the inlet end of the Laval nozzle, the outlet end of the Laval nozzle is connected to the inlet end of the spray precooling pipe, and a plurality of atomizing nozzles are evenly distributed on the spray precooling pipe.

2. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 1 is characterized in that: The spray inlet pipe is a cylindrical pipe with a length of 100 mm and a width of 20 mm.

3. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 2 is characterized in that: The front end of the Laval nozzle gradually contracts toward the middle part, and the middle part gradually expands toward the rear end.

4. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 3 is characterized in that: The spray precooling pipeline is cylindrical, and 30-50 atomizing nozzles are arranged per square centimeter on the spray precooling pipeline.

5. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 2 is characterized in that: The spray inlet pipe includes an inner container, an insulation layer, a vacuum layer and an outer wall from the inside to the outside.

6. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 1 is characterized in that: The atomizing nozzle adopts a fan-shaped outlet, and the central angle range of the fan-shaped outlet is controlled between 90° and 120°.

7. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 6 is characterized in that: The atomizing nozzle comprises a nozzle body, a gas-liquid diversion inlet, a tapered cavity, a jet section, an adjustable rolling joint and a nozzle outlet, wherein the gas-liquid diversion inlet is arranged at the inlet end of the nozzle body, the tapered cavity is connected to the outlet end of the gas-liquid diversion inlet, and the diameter of the tapered cavity gradually decreases from one end close to the gas-liquid diversion inlet to the other end away from the gas-liquid diversion inlet, the jet section is connected to the outlet end of the tapered cavity, the diameter of the jet section is larger than the diameter of the outlet end of the tapered cavity, and the diameter of the jet section gradually decreases from one end close to the tapered cavity to the other end away from the tapered cavity, and the nozzle outlet is arranged at the outlet end of the jet section, and the nozzle outlet is movably connected to the outlet end of the jet section through the adjustable rolling joint.

8. The injection device for improving the precooling effect of the vehicle-mounted liquid hydrogen tank according to claim 7 is characterized in that: A gas-liquid guide device is provided at the gas-liquid guide inlet, and the gas-liquid guide device includes a liquid guide inlet and multiple gas guide inlets. The gas guide inlets are evenly arranged along the circumference of the liquid guide inlet, and the diameter of the liquid guide inlet is larger than the diameter of the gas guide inlet.

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